Thursday, March 21, 2013

Population Size =/= Consumption

     As Matt talked about in class and I previously mentioned in this blog, one of the major causes behind conservation issues is human population growth and consumptive demand. In December 2012, an editorial was published in Conservation Biology discussing just that (Allendorf & Allendorf 2012).

     It was short, succinct and well written. It explained the causative factors behind the population boom of the past two centuries and how it will end within 100 years. Their view of the future was a reasonably positive one as they provided concrete ideas on how we can address population growth and consumption now in order to minimize conservation issues in the future.

     According to the editorial, the human population became an environmental problem only in the past 150ish years. Prior to the 1800s, mortality and fertility was high. People lived to an average age of 35 and each woman had on average 6 children. The world’s population was about 1 billion with a minimal environmental impact.

     Then in the 1800s and 1900s, medicine and hygiene improved. People began to live longer and their children had better chance of having kids of their own. Fertility rates began to fall from 6 to 2.5 kids per woman. According to the article, fertility levels stabilized in the late 1800s in developed countries and around 1950 in others. Because women could be reasonably sure their kids would survive to adulthood, they gave birth fewer times.

      By the early 1960s population growth rate peaked. This means that while the world’s population is still rising but it isn’t growing nearly as fast as it once was.

     With regards to the future, the authors suggest that population growth will peak by 2100 at around 10 billion. Furthermore as fertility rates are lower now than in the 1700s, it is likely that the world’s population will decline slowly throughout the 22nd century.
The authors seem to be describing the trend shown here...
     The authors also provided suggestions to deal with conservation issues by addressing the root cause of population growth and over-consumption:
     1)      Support family planning and contraception. This will help women control the number of children they want to have, and in turn minimize population growth.
     2)      It is not population size but spatial distribution that matters – therefore work to concentrate populations in centers away from sensitive environments.
     3)      Consumption is not correlated with population size but rather with the number of population ‘units’ (households) present. Therefore seek to reduce consumption by providing social and economic benefits to these population ‘units’. Make consumption reduction matter.

     I found these suggestions intriguing. The idea that it’s not the number of people that matter but where they are and how they organize themselves is interesting – consumption is independent of population size.

     Furthermore their prediction that populations will stabilize and even decline, it changes our perspectives on conservation. I think dealing with a constant predictable pressure would be better than the endless upward trend we are experiencing now.

Allendof, T. D., and K. Allendorf. 2012. What Every Conservation Biologist Should Know about Human Population. Conservation Biology 26:953-955.

Wednesday, March 6, 2013

Lyall's Mariposa Lily

Lyall’s Mariposa Lily, AKA Cat’s Ear Lily
Calochortus lyallii

I first heard about this species of Mariposa lily in first or second year; I cannot remember which. It was mentioned just as a passing comment by a professor (Lyn, I think), about there being a rare variation on the Sagebrush Mariposa Lily that is so prevalent in the grasslands around Kamloops. Apparently it only grew down south by the border – in the Boundary region perhaps, or maybe down in the Okanagan.

This past summer I spent two months taking soil samples in the grasslands throughout southern BC. Once we started sampling in the Okanagan, I kept my eyes peeled for this lily, much to the chagrin of my field partner. At the time, the Sagebrush Mariposa lilies were in full bloom and spectacular… but I never once saw Lyall’s Mariposa lily.  

One day we were heading to two sampling sites very close to the Canada-US border – one was on the south side of Kruger Mountain, the other was on the south side of Black Mountain. We managed to get to the Kruger Mountain site easily enough, but on the way to the Black Mountain site the road was flooded so we turned around. The next day we drove on to the East Kootneys and I looked no more for this beguiling plant.

I did not think again of the Cat’s Ear lily until a few days ago when I found an entry in the eFlora BC database (Klinkenberg 2013). Like most of the plants on eFlora, a map is provided showing the GPS coordinates where the species has been observed in the past. On it I zoomed in… and saw that one of the only places in all of BC (and for that matter, all of Canada) that this species is found is on the south side of Black Mountain. In the Chopaka region of the Okanagan-Similkameen. Less than 50 meters up the hill from where we turned around this summer.

I was so close and yet so very far away!

I suppose why I am sharing this story of hunting and not finding this lily is because as a species, it raises a unique conservation question.
In all of Canada, there are only five populations of Lyall’s Mariposa lily, scattered on and around this one small mountain in the Southern Okanagan. Because of a small population size and threats from cattle grazing, this species was listed by COSEWIC in 2001 as threatened (Klinkenberg 2013, Miller 1999).
However, it is very abundant further south in Washington and Oregon, so the species won’t be extinct if the population on Black Mountain dies out. But the Black Mountain population is ours; it is Canadian.

Therefore, how do we approach the conservation of this species given that in Canada it is endangered, while throughout the entirety of North America it is doing quite fine (Encyclopedia of Puget Sound 2011)?

Should we act to conserve this species or not? How do we decide?

Miller, M. T., and G. W. Douglas. 1999. Status of Lyall’s Mariposa Lily, Calochortus lyallii (Liliacaeae), in Canada. Canadian Field-Naturalist 113:652-658.

Klinkenberg, B. 2013. Calochortus lyallii Baker. E-Flora BC: Electronic Atlas of the Plants of British Columbia, University of British Columbia, Vancouver. Available from

Encyclopedia of Puget Sound. 2011. Calochortus lyallii. Puget Sound Institute. Available from

Thursday, February 14, 2013

The Rise of the Machines

According to Matt, today’s top conservation issues include the introduction of invasive species and the spread of diseases, climate change, ocean acidification, habitat alteration, overconsumption and an increasing world population. And while each of these issues are complex and have a multitude of contributing factors, I see one constant in every case: the rise of machines. In my opinion, increasing mechanization over the past 100 years directly resulted in the conservation issues we now face today.

First, let’s consider the introduction of invasive species and the spread of diseases across the globe. This is because people all over the world are now able to interact and travel to places they have never gone before. And how is it that people (and their unintended hitch-hikers) can visit the world over? Simple – by jumping aboard machines that allow us to travel at fantastic speeds across great distances (NAP 2006, 2013).

Second, climate change. According to the Government of Canada, the two major human factors behind climate change are the use of fossil fuels and converting land for logging or agricultural purposes (GC 2009). So because fossil fuels are used by most of our machines – cars, planes, power plants, and refineries – they directly affect our climate. What is not so obvious, however, is the effect this release of carbon dioxide has upon our oceans.
Specifically, as fossil fuels are burnt by machines and carbon is released from converted land, carbon dioxide enters the atmosphere. Then a large percentage of this gas is re-absorbed by the ocean – and due to the bicarbonate equilibrium its pH decreases and our oceans acidify (NOAA 2013).
As for land conversion, machines are again almost entirely responsible for the alternation of natural landscapes into human-dominated ones. Consider current forestry and farming operations – almost all the work is done by people using machines. Previously only hand-saws and scythes were used… but have now been replaced by chainsaws, logging trucks and combines (CE 2012, NAE 2013).
So first off, without machines we wouldn’t have the current large-scale forestry or agricultural operations which are leading to habitat loss for so many species, and secondly we wouldn’t be altering the climate and oceans to the degree that we are now.

Furthermore, the impact of these machines has been compounded as the world’s population exploded over the past 100 years. Our demands and consumption of natural resources also increased, as more food and land was required to feed, clothe, house and entertain the world’s population. As has been described above, these actions are almost entirely fulfilled through the use of machines.

            So if not for machines, we wouldn’t be where we are now. But on the other hand, the development of mechanization and fuel-power are directly responsible (in one way or another) for causing the conservation issues we face today. However, (unlike in the movies) it is people who are driving these machines. So I suppose, we really oughtn’t blame machines for our troubles at all – rather, we should blame ourselves.

References Cited:
Canadian Encyclopedia (CE). 2012. Forest Harvesting. Retrieved February 14, 2013, from

Government of Canada (GC). 2009. Causes of Climate Change. Retrieved February 14, 2013, from

National Academies Press (NAP). 2006. The Impact of Globalization on Infectious Disease Emergence and Control: Exploring the Consequences and Opportunities, Workshop Summary - Forum on Microbial Threats. Retrieved February 14, 2013, from

National Academy of Engineering (NAE). 2013. Agricultural Mechanization - Greatest Engineering Achievements of the Twentieth Century. Retrieved February 14, 2013, from

National Oceanic and Atmospheric Administration (NOAA). 2013. Ocean Acidification. Retrieved February 14, 2013, from 2013. General Information About Invasive Species. Retrieved February 14, 2013, from

Thursday, January 31, 2013

Atrazine and Amphibians


            Atrazine – or 2-chloro-4-6-s-triazine – is one of the most widely used herbicides in the continental United States (1). Since its introduction in 1959 (2), farmers have been applying atrazine to prevent the growth of weedy grasses and broadleaved plants. Currently over 27 000 tonnes is applied annually to corn, sorghum and sugar cane (1). And that is fine, because it only kills weeds… right?
Well, in 2002, Dr. Tyrone Hayes of UC Berkeley published a study investigating atrazine’s effects upon amphibian development. Both in the lab as well as at atrazine-contaminated sites throughout the US, he found that frogs exposed to atrazine developed abnormal gonads (3). In many cases, both male and female reproductive organs were present on the same frog!
 His findings lead to widespread public outcry and concern, as well as calls for more studies to be conducted. Over the past ten years, Dr. Hayes has published ten more studies all with similar findings: that atrazine disrupts the endocrine system of amphibians, reptiles and fish and can result in males developing female reproductive parts (4).
On the other hand, Syngenta – the company that sells atrazine in the United States – conducted several studies of their own, and in every one concluded that atrazine had no effect upon amphibian development (5).

So… who is correct? Does atrazine affect frogs as Dr. Hayes found, or is Syngenta right in that atrazine is harmless?

However in

I think this is a quandary worthy of discussion: Should a company study the health and environmental impacts of their own products, at the risk of their findings negatively affecting their own profit margin? Or if you trust the findings of Syngenta, how did Dr. Hayes’ find what he did in the first place?

How do we know which studies to believe?

As scientists, what we believe should be irrelevant to our decision making; it should be what we think. But what are we to think about this issue when the ‘truth’ is so unclear?

I suppose the next question we should ask is, do we care about the effect of atrazine upon amphibian species, or do we spend our time and money upon a less controversial issue? On one hand, the prevalence of use of this herbicide means any impact it has would be massive and widespread. But on the other hand, if it were not used, food would likely cost a fair bit more (6).

So what do we choose – the science of Syngenta or the findings of Dr. Hayes? Do we try to save the amphibians or continue to have cheap food with a side helping of atrazine?

On a side note, the EU has not allowed the use of atrazine in their food system.

1.    U.S. Environmental Protection Agency. 2013. Atrazine Updates. Available from
AGsense. 2013. Atrazine Regulatory Issues. Available from
Nature. 2002. Feminization of male frogs in the wild. Available from
Web of Knowledge. 2013. Web of Science. Available from
AGsense. 2013. Atrazine and Frogs. Available from
6. Ackerman F. 2007. The Economics of Atrazine. Int J Occup Environ Health. 13:441-449.

Thursday, January 17, 2013

Plants in Peril...?

Rosy Owl-Clover (Orthocarpus bracteosus) – A Red-listed species native to BC's west coast. I saw a very similar species this summer while working in the East Kootneys. Plants are only 20 cm tall and their flowers are a brilliant pink – the most brilliant color I have ever seen in a wildflower!!

As I was looking through the Habitat Conservation Trust Foundation’s list of funded projects (HCTF 2012), I was struck by how very few dealt with plants. From the HCTF, people have received funding to enhance the habitat of Lytton elk, maintain salmon and trout spawning channels, restore western painted turtle habitat, and prevent rattlesnakes from entering human-inhabited areas. Other funded projects aim to identify the bat species present during the winter in Southern BC while more still plan to determine population sizes for BC’s steelhead and sturgeon fish, grizzly bears in the Stein valley, and goats in the Shuswap region. And while I agree with the need and idea behind many of these projects, I cannot help but wonder – what about the plants?
            In BC, there are over 1100 species and subspecies of plants that are either red or blue listed (BC Ministry of Environment, 2013). That is, in BC alone there are over 1100 plant species that are endangered, extinct, extirpated, of special concern, or are threatened. Comparatively, there are only 400 animals in to BC that fall into these five categories (BC Ministry of Environment, 2013).

            Despite the overwhelming numbers of red and blue-listed plants, all of the projects I saw on the HCTF's website focus upon the “habitat protection” of various animals (HCTF 2012). Nowhere did I find a project with the purpose of protecting a specific endangered plant species. And while protecting the habitat of other animals does in turn protect the plant species that live there, I cannot help but wonder if we are making a mistake by not explicitly protecting our threatened plant species. I mean, it isn’t like plants are entirely useless – all animals (including ourselves) depend upon plants to provide us with oxygen to breathe, food to eat, material to make shelter of as well as to maintain countless other ecosystems services.
            I suppose the point I am trying to make in writing this blog post is thus: Given that there are almost three times as many endangered plant species than there are animals of concern in BC, is it a good idea to focus only upon these animals and not on the plants that all animals depend on? That is, if we forget to protect the plants, where will it leave the animals?

BC Ministry of Environment. 2013. Plants & animals search results [Red & blue list] - BC Species and Ecosystems Explorer. BC Ministry of Environment, BC. Available from (accessed January 15 2013).

Habitat Conservation Trust Foundation (HCTF). 2012. Approved project list 2012-2012. HCTF, BC. Available from (accessed January 15 2013).